Investigations of three, four, and five-particle exit channels of levels in light nuclei created using a 9C beam

TL;DR

This study investigates multi-particle decay channels in light nuclei created by a 9C beam, revealing detailed decay mechanisms, intermediate states, and specific decay pathways such as two-proton and four-body decays.

Contribution

It provides new insights into the decay processes of light nuclei, including the identification of sequential and prompt decay modes and the spin states involved.

Findings

8C ground state decays via two-step 2p emission passing through 6Beg.s.

8B's isobaric analog undergoes two-proton decay to 6Li.

A 10C state decays promptly into 2p+2alpha with diproton enhancement.

Abstract

The interactions of a E/A=70-MeV 9C beam with a Be target was used to populate levels in Be, B, and C isotopes which undergo decay into many-particle exit channels. The decay products were detected in the HiRA array and the level energies were identified from their invariant mass. Correlations between the decay products were examined to deduce the nature of the decays, specifically to what extent all the fragments were created in one prompt step or whether the disintegration proceeded in a sequential fashion through long-lived intermediate states. In the latter case, information on the spin of the level was also obtained. Of particular interest is the 5-body decay of the 8C ground state which was found to disintegrate in two steps of two-proton decay passing through the 6Beg.s. intermediate state. The isobaric analog of 8Cg.s. in 8B was also found to undergo two-proton decay to the isobaric analog of 6Beg.s. in 6Li. A 9.69-MeV state in 10C was found to undergo prompt 4-body decay to the 2p+2alpha exit channel. The two protons were found to have a strong enhancementin the diproton region and the relative energies of all four p-alpha pairs were consistent with the 5Lig.s. resonance.